Answer:
the correct answer is A
Explanation:
definition of a decomposer is an organism, especially a soil bacterium, fungus, or invertebrate, that decomposes organic material.
so A is the answer
If brainiest is earned its greatly Appreciated
Frog RBCs contain a DNA-bearing nucleus that is visible in the center of the cell. Human RBCs do not possess nucleus along with other cell organelles such as mitochondria, Golgi apparatus and endoplasmic reticulum in order to accommodate greater amount of haemoglobin in the cells. Denucleation of rbcs is an adaptation, Which makes the mammalian red blood cell effective at transporting oxygen/eliminating CO2.
Answer:
Hemoglobin is responsible for binding and transporting oxygen in the body. It is a tetrameric protein that is found in high concentration in red blood cells (erythrocytes, red blood cells). Each hemoglobin molecule is made up of four subunits: two of the alpha type and two of the beta type, and each subunit can bind an oxygen molecule through its heme group.
Structure studies have shown that hemoglobin can adopt two conformations, called T (tense) and R (relaxed). Deoxyhemoglobin (in blue) is in state T, and the union of oxygen (in red) causes the transition to state R. The animation shows a close view of the heme group (in white, balls and rods) of one of the subunits of hemoglobin. In the deoxygenated state (T), the iron atom is not coplanar with the rest of the heme group due to its association with the histidine side chain. The union of oxygen displaces the iron atom so that it remains coplanar with the rest of the heme group, which in turn drags histidine, producing a larger-scale conformational change that affects the entire protein.
Hemoglobin can be considered as a tetramer formed by two alpha-beta dimers. The conformational change associated with the transition from T to R mainly affects the relative position of these two dimers (rather than the interactions between the alpha and beta subunits within a dimer). This is illustrated in the last stretch of the animation (drawn in black and white).
C. <span>When water in a lake freezes, it floats, providing insulation for organisms below.
This </span> best describes an effect of the low density of frozen water in a lake.
